Three of six suspects are still uncaught after people who “knew each other” had an “interaction” in the store, police said.

The shooting Tuesday inside a South Carolina Walmart is believed to involve two groups of people in gangs exchanging gunfire, Lancaster Police Chief Don Roper said Thursday at a news conference.

"It didn't seem to be random," said City of Lancaster Police Department Chief Don Roper. He noted that investigators are trying to determine exactly how the male victims became involved.

Lancaster Police Chief Don Roper said none of the people involved were employees, and investigators believe they knew each other. “These were people that came from outside and had an interaction ...